Piano action



Aug. 19,1947. A. P. BRowN PIANO-ACTION Filed Jan. 9, i946 INVENTOR; ALEXANDER P. BROWN BY l/KLHM' ATTORNE)l Patented Aug. 19, 19K-i7 UNITED FEANO ACTION Alexander P. Brown, Becchhurst, Long Island, N. Y.

Application January 9, 1946, Serial No. 639,923

(Cl. SLi-240) 9 Claims.

My invention relates to piano actions and, more particularly, to actions for spinets or upright pianos of restricted dimensions. An object of my invention is to provide an action which can be inserted in a piano of a height not much exceeding the height of the keys.

In the prior art, this object has been attained by providing mechanisms connecting the key with an actuating element positioned at a lower level whereby the height of an action of otherwise more or less conventional structure is reduced. Such devices are known as underslung actions. They have several severe disadvantages. The mechanism interposed between the key and the proper action increases the number of parts required, requires higher expenses, makes the structure more complicated, makes the proper adjustment more dinicult and less reliable and results in a mushy touch and tones of poor duality.

Further objects of my invention are to avoid these drawbacks, to actuate the proper action by direct blow or stroke of the key, and, thereby, to obtain tones of perfect quality.

Other objects are to provide a jack with a lower end positioned considerably lower than the key; to provide a hammer with a butt positioned near this lower jack end; and to provide for different engagements between this hammer butt and this jack end, one engagement by which the jack causes the hammer to swing toward the sounding string or to swing back into the position of rest, and another engagement by which the jack acts as a back check for the hammer.

Further objects are to provide a damper which is withdrawn from the damping position by the jack at the end of a stroke; and to the jack, the hammer and the demper in a narrow space located at the back side oi the key.

Still other objects are to arrange the hammer and the jack at a short horizontal distance from each other; to facilitate, thereby, the proper engagement between these parts; to provide, thereby, for a small horizontal measure of the action and of the piano; and to provide a structure of the hammer rest which can be positioned in the narrow space between the hammer and the jack.

Still further objects are to provide means tripping the jack out of the driving engagement with the hammer butt and into a position where the jack is ready to act as a back check; and to provide a jack trip screw inserted in a lever arm which turns relatively to the jack when the key is struck whereby this screw trips the jack at the end of a key stroke.

Still other objects are to provide for insertion and removal of the action as a unit including the keys; and to provide a frame affixed to the key bed and supporting fixed pivots of the action.

Still further objects are to reduce the number of parts, and to simplify the structure oi a piano action of this type.

Still other objects and advantages will appear from the following description of an exemplifying embodiment of my invention, from the appended claims and from the accompanying drawing in which the figure shows a vertical, partially sectional side view of this embodiment.

It should be noted that, throughout this specication and claims, the front side is understood to be the side facing the performer or the left side in the drawing, and the back side to be the side facing the sound string or the right side in the drawing.

Referring to the drawing, numeral I indicates a key shown broken off, the front part of this key being omitted. This omitted part may be connected in well known or conventional manner, turnably, to a not shown part of a key bed or board 2. The shown back part of the key bed 2 may have an upper surface provided with a pad it on which the back part of the key I rests when the key is not operated.

The key l can be operated either by the hand of a performer or by a pneumatic action which may move a wire 3 in vertical direction. 'Ihe wire 3 may pass slidably through an opening of a block l aiiixed to the key bed 2 by a screw 45 and may have an upper end provided with a head 5 contacting a padded lower surface it of the key i. In both kinds of operation, the back end of the key l moves upward when the key is struck.

A capstan t is adjustably inserted in the upper surface of the back part of the key l and contacts a padded lower surface lil of a lever arm 1 which has a xed pivot 8 positioned, in horizontal direction, beyond the back end of the key l. The arm 'i is raised when the key is struck. The pivot 8 connects the arm 'i rotatably to a part @8 which is affixed, by a screw 49, to a block 50 forming a part of the pianos stationary structure.

A jack 9 is hinged to the arm l at a pivot point iii positioned between the capstan 6 and the pivot it. A spring ii has a fixed end l2 and a movable end i3 contacting the upper end of the jack 9 and urging the same in counter-clockwise direction around the pivot I 6 and, at the same time, urging the jack and the arm 'l down.

A jack trip screw Iil is adjustably inserted in the arm 'I between the pivots u and itl and over a projection lil of the jack t'. The lower surface of the screw I4 contacts a padded surface 5I of the projection I5 at the end oi a key stroke, whereby the jack is tripped or slightly turned around the pivot It in clockwise direction.

The jack 9 extends from the pivot I9 down in an oblique direction and has a lower end positioned considerably below the level of the key or of the key board. This lower end is preferably shaped like a hammer head and has two projections, a back projection. Iii and a front projection I1 which are adapted to engage the hammer butt in different positions of the action as will be described later.

The arm I and the jack l0 may be made, for example, of aluminium.

A hammer has a shank I8 which, in the position of rest, is situated at a short distance from the jack 9, and at the back side thereof. A butt I9 is affixed to the lower end of the shank I3 and has a recess 2D at the front side, facing the projection I6, This recess is releasably engaged by the projection I6 which pushes the butt I9 up when the key is struck and the jack moves up, and pushes the butt i9 down when the key is released and the jack moves down. The surfaces of the recess 20 which are contacted by the projection I6 may be padded with felt layers 52 and l53, and a thin layer 2| of suitable protective material, for example, buckskin, may be placed over these felt layers and adjoining parts of the butts surface. The hammer butt I9 .has a pivot or hinge 22 positioned farther to the back side than the recess 20. The stationary part till of the hinge 22 is aifixed to a fixed block 23 by a screw 55.

An extension is affixed to the butt I9 and, preferably, comprises a part 24 and a wire 25 connecting the part 24 with the main part of the butt I9. The wire 25 may be bent for adjustment of the position of the part 24. The part 24 has a V-shaped recess 2G which may be padded with felt 56 covered with a layer of leather 2l. rEhe part 24 is so adjusted that the projection I'I of the jack engages the recess when the jack is tripped into its most forward position at that time when the hammer rebounds whereby the jank acts as a back check.

A head 28 is ailixed to the upper end of the shank I8. When the hammer swings around the pivot 22 in clockwise direction, the head 23 hits a sounding string 29 in the position shown in dotted lines.

A hammer rest 3!) forms a stop for counterclockwise movement of the hammer. In the position of rest, the shank ifi contacts a padded sul; face of the hammer rest 3B. The latter is positioned in the narrow space between the shank I8 and the jack 9, and suitable clearance is left between the hammer rest and the jack. In order to make this arrangement possible, the structure of the hammer rest comprises, in contradistinction from the usual wooden bar or rail, a steel rail 3| which has a U-shaped cross-section having short legs bent into tight engagement with the pad of the hammer rest fill. This structure can be made suiiiciently strong without requiringr much space in the direction perpendicular to the shank I8 and makes it possible to arrange the jack 9 and the shank Iii at a short distance from each other.

A damper comprises a preferably vertically positioned arm 32, turnable around a fixed pivot 33, a head 34 and a wire tt connecting the head aos all with the upper end of the arm 32. A spring has a nxed end and a movable end 31 urging the damper into contact with the string 29. The pivot connects the arm 32 rotatably to a part 5i' which is affixed, by a screw 58, to a stationary part, for example, to the block 23.

The damper is so connected to the jack 9 that the latter withdraws the head 34 from the string when the jack is tripped into its most forward position. Preferably this connection is constituted by a wire 38 having a front part 39 which .is so bent that it is positioned across a padded front surface 59 of the jack 9. A backward bent end :i9 of the wire 38 passes slidably through this surface and the jack 9. The other end of the wire is affixed to the damper arm 32 and may form a hook 4I passed through a padded part iii] of the arm 32.

The stationary parts of the action may be mounted on a common bracket 42. For example, the block 23 carrying the pivots 22 and 33 of the hammer and the damper may be supported by bracket e2 and may be affixed thereto in usual m. ,.ner. Other stationary supports of the action be affixed to the same bracket in similar well known manner, and the bracket 42 may be affixed to the main body or case of the piano` in well known and separable manner. The case some parts of the bracket 42 are omitted in the drawing. Several brackets 42 may be arranged, For example such brackets may be positioned at each end of a row of parallel actions. According to the invention, the key bed is not directly connected to the oase of the piano but is mounted on the bracket 42, whereby the keys and the key bed together with the other parts of the action form a unit which can be inserted in an upright piano in assembled and adjusted condition and can be taken out in assembled condition for readjustment or repair.

The described piano action operates as follows:

When the key I is struck. the capstan 6 drives the arm 'I up, raising the jack 9, whereby the projection l, engaging the recess 20 and pushthe upper surface thereof, turns the hammer around the pivot 22 into the position where the hammer head 28 strikes the string 29 as shown in dotted lines.

The jack trip screw I4 is so adjusted that, a short time before the key stroke is completed, the jack is turned in clockwise direction around the pivot I0 sufficiently to withdraw the projection lil from the butt recess 20. Simultaneously, the jack 3 pulls the wire 33 and, thereby, turns the damper a little in counter-clockwise direction around the pivot 33 whereby the damper head 3e is withdrawn from the string 29. Then, the hammer, being disengaged from the projection It of the jack, rebounds and is caught by the jack projection Il as described before.

When the key I is released, it returns into the .shown position of rest. At the same time, the spring II urges the jack 9 and the arm I back into the shown position. The jack projection I'I is disengaged from the recess 26, the projection Iii entering again the recess 20 and pushing the lower surface thereof down whereby the hammer is returned into the position shown in full lines.

I desire it understood that my invention is not confined to the particular embodiment shown and described, the same being merely illustrative, and that my invention may be carried out in other ways without departing from the spirit of my invention as it is obvious that the particular embodiment shown and described is only one oi the many that may be employed to attain the objects of my invention.

Having described the nature of my invention, what I claim and desire to protect by Letters Patent is:

l. A piano action comprising a key having a back part moving up when the key is struck, an arm having a nxed pivot positioned farther backward than the back end of key and having a part extendingA over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and having a back projection, and a hammer having a shank positioned at the back side of said jack and having a butt aiiixed to the lower end of said shank, and having a recess at its front side and a fixed pivot, said recess and said jack projection releasably engaging each other.

2. A piano action comprising a key having a back part moving up when the key is struck, an arm having a iixed pivot positioned farther backward than the back end of said key and having a part extending over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and forming a head having a back and a front projection, and a hammer having a shank positioned at the back side of said jack and having a butt affixed to the lower end of said shank, and having a recess at its iront side and a i-ixed pivot, said recess and said jack projection releasa'bly engaging each other, said butt having an extension with a recess, said extension being so positioned that said extension recess engages said front projection of the jack when said hammer rebounds.

3. A piano action. comprising a key having a back part moving up when the key is struck,

an arm having a fixed pivot positioned farther backward than the `back end of said key and having a part extending over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably #lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack and having a butt ailixed to the lower end of said shank, and having a recess at its iront side and a fixed pivot, said recess and said jack projection releasably engaging each other, a spring urging said jack down and its lower end into said engagement, and a jack trip screw inserted in said arm between said arm pivot and said jack hinge, said jack having a projection contacted by said screw at the end of a key stroke whereby said jack is tripped out of said engagement.

4. A piano action comprising a key having a back part moving up when the key is struck, an arm having a iixed pivot positioned farther backward than the end of said key and having a part extending over said key part and drivingly contacted by the saine whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and forming a head having a back and a front projection, a hammer having a shank positioned at the back of said jack and having a butt aiiixed to the lower end of said shank, and having a recess at its front side and a xed pivot, said recess and said jack projection releasably engaging each other, said butt having an extension with a recess, said extension being so positioned that said extension recess engages said front projection of the jack when said hammer rebounds, a spring urging said jack down and its lower end into engagement with said front recess of said butt, and a jack trip screw inserted in said arm between said arm pivot and said jack hinge, said jack having a projection contacted by said screw at the end of a key stroke whereby said jack is tripped out of the engagement with said front recess and is turned into engagement with said extension recess.

5. A piano action comprising a key having a back part moving up when the key is struck, an arm having a fixed pivot positioned farther backward than the back end of said key and having a part extending over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack and having a butt affixed to the lower end of said shank, and having a recess at its front side and a fixed pivo-t, said recess and said jack projection releasably engaging each other, a damper having a xed pivot positioned considerably lower than said key, and a wire connecting said damper to said jack.

6. A piano action comprising a key having a back part moving up when the key is struck, an arm having a fixed pivot positioned farther backward than the back end of said key and having a part extending over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack and having a butt aiiixed to the lower end of said shank, and having a recess at its front side and a fixed pivot, said recess and said jack projection releasably engaging each other, a damper having a nxed pivot positioned considerably lower than said key, and a wire having one end hooked into said damper and another end hooked from the front side into said jack.

'7. A piano action comprising a key'having a back part moving up when the key is struck, an arm having a iixed pivot positioned farther backward than the back end of said key and having a part extending over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and having a, back projection, a hammer having a shank positioned at the back side of said jack and having a butt axed to the lower end of said shank, and having a recess at its front side and a xed pivot, said recess and said jack projection releasably engaging each other, and a hammer rest positioned between said shank and said jack and comprising a steel rail of U-shaped cross-section.

8. A piano action comprising a key having a back part moving up when the key is struck, an arm having a fixed pivot positioned farther back-- ward than the back end of said key and having a part extending over said key part and drivingiy contacted by the same whereby said part moves up when the key is struck, a jack hinged to said arm and extending from said hinge down, the lower end of said jack being positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack and having a butt aixed to the lower end of said shank, and hav ing a recess at its front side and a iixed pivot, said recess and said jack projection releasahiy engaging each other, a stationary block supporting said hammer pivot, a key bed supporting said key, and a bracket supporting said block and said key bed.

9. A piano action comprising a key having a back part moving up when the key is struck, an

arm having a fixed pivot positioned farther backward than the back end of said key and having a part extending over said key part and drivingly contacted by the same whereby said part moves up when the key is struck, a jack hinged te said arm and extending from the said hinge down, the lower end of said jack being positioned considerably lower than said key and having a back projection, a hammer having a shank positioned at the back side of said jack and having a butt afiiXed to the lower end of said shank, and having a recess at its front side and a xed pivot, said recess and said jack projection releasably engaging each other, a key bed supporting said key, stationary blocks supporting said pivots, and a bracket supporting said key bed and said blocks whereby said action forms a unit including said key.

ALEXANDER P. BROWN. 

